Cantilevered folding gates are already known; European patent EP 1 595 050 B1 for example describes a number of embodiments of such folding gates. The described folding gates comprise: a column, a first gate leaf which is hingedly connected to the column, a second gate leaf which is hingedly connected to the first gate leaf, drive means designed to drive the first gate leaf and a transmission mechanism designed to transmit the movement of the first gate leaf to the second leaf so that the first and second gate leaf open or close simultaneously by folding. Furthermore, a projecting gearwheel is attached to the second gate leaf, whose axis of rotation is concentric with that of the hinge between the first and second gate leaf, in which the gearwheel remains statically arranged with respect to the second gate leaf and in which rotation of the gearwheel about its axis of rotation causes a rotation of the second gate leaf about said hinge.
According to a first embodiment, the transmission mechanism comprises an arm which is statically connected to the column and a rod, one end of which is hingedly connected to the arm and the other end of which is provided with a toothing which meshes with the abovementioned statically arranged gearwheel. When the first gate leaf is driven, the gate leaves will open or close simultaneously by folding.
However, this embodiment has the drawback that the opening or closing of the gate leaves by folding does not take place in a linear fashion, as a result of which the tip of the gate (end of the second gate leaf) makes a non-rectilinear movement when the gate opens or closes. In EP 1 595 050, this is solved by the second described embodiment in which the transmission mechanism now comprises a fixedly arranged chain wheel which is connected to the column and a transmission means in the form of a chain or belt between the fixedly arranged chain wheel and the statically arranged chain wheel at the position of the connection between the first and second gate leaf instead of the above-described mechanism of rods. In this embodiment, a guide wheel is provided on the end of the second gate leaf. However, this embodiment has the drawback that there is a risk that the chain will expand due to frequent use, as a result of which the orientation of the second leaf is no longer clearly determined by the movement of the first leaf. The second leaf can—within the limits of the expansion—assume any orientation, which disrupts the simultaneous movement of the two leaves.
An additional drawback of the embodiments shown in EP 1 595 050 is the fact that the transmission mechanism is fixedly connected to the column and is thus difficult to replace.